1. Field of the Invention
The present invention relates to a machining apparatus, such as a numerically controlled apparatus (hereinafter, NC apparatus) or programmably controlled apparatus (hereinafter, PC apparatus) that controls the machining operations of a machine tool and, in particular, to an NC apparatus or PC apparatus, including method therefor, which is capable of displaying in an easily identifiable manner the operation of each axis of a machine tool.
2. Description of the Related Art
FIG. 8 is a view illustrating the hardware configuration of a conventional NC apparatus and the main sections of the numerically controlled apparatus. In FIG. 8, reference numeral 1 denotes a numerical control section, 2 denotes a storage section in which machining programs and various parameters are stored, 3 denotes a display control section for outputting various machining information based on the machining programs and various parameters to a display section 4, having a CRT monitor, and 5 denotes an operation section which is integrally provided with the display section 4. Various operations performed on an NC apparatus, using a machine tool, are input to the numerical control section 1 by way of an operation control section 6. Reference numeral 7 denotes an axis drive section for each of the axes of a machine tool 8 which controls the driving of each axis on the basis of machining data obtained from computations made by the numerical control section 1. The machine tool 8 is provided with two tool turrets 17 and 18, each having one or more tools that are rotatable about an axis into a machining position. A workpiece 16 is mounted on a so-called C axis, which is a main axis of the machine tool 8. The tool turret 17 has axes X1 and Y1, and the other tool turret 18 has axes X2 and Z2. The tool turrets are selectively moveable in their axial directions to permit selected tools to engage the workpiece and perform a desired machining operation.
The conventional NC apparatus is constructed as described above. The numerical control section 1 reads out and analyzes machining programs which have been previously stored in the storage section 2, determines the movement quantity of each axis, and outputs it to the axis drive section 7. The axis drive section 7 controls the machine tool 8 to perform a desired machining on the workpiece 16. Specifically, section 7 converts the axis movement quantity into drive signals that can drive a motor section (not shown) disposed in the machine tool 8 in order to rotate the workpiece 16 and move the tool turrets 17 and 18 according to the stored programs.
At the same time, the numerical control section 1 determines the current position of each axis in the coordinate system, on the basis of the previous axis position and axis movement quantity, and displays this position data on the display section 4 by way of the display control section 3. That is, axis names 9 and data 10 indicating the current position of each axis corresponding to a name of the axis are displayed by the display section 4.
Concerning the movement instruction to each axis, the arrow direction is denoted as + and its opposite direction as - in FIG. 8. Since the position data 10 matches the instruction of the machining program, the data 10 shows only the current position of each axis that increases or decreases in accordance with the + or - instruction in the coordinate system of the machine tool.
The rotation of the workpiece 16 is represented by the movement about the C axis. Rotation is to the right (clockwise) for the + instruction and to the left (counterclockwise) for the - instruction.
In the above-described conventional NC apparatus, there has been a disadvantage in that, when an operator desires to confirm the operating status of a machine tool on a display section, he cannot know immediately in which direction each axis of the machine tool has actually moved and, therefore, sometimes he must confirm the operating status of the machine tool by direct inspection of the tool. In particular, where a certain axis of a machine tool operates in a wrong direction because an error has been made regarding the instruction direction of a machining program, a problem arises in that it is difficult to know that the machine tool is operating in a wrong direction from the display of the current position by the display section. Similarly, if the motor is faulty, the machine may not respond correctly, in the manner commanded by the programs. Of course, where there are keyboard inputs to control the movement of the tools or workpiece, errors can easily occur which cause the machining to proceed in the wrong direction.
Even if the above errors may be detected by an automatic detector that can give an alarm, often the operator will be quicker to recognize the mistakes than a detector with pre-programmed limits.
The present invention has been devised to solve the above-mentioned problems.
Accordingly, an object of the present invention is to provide a machining apparatus having a display, and method therefor, which provides an operator with the operating status of each axis of a machine tool such that it can be identified rapidly and accurately.